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Surface Preparation
Published in Karan Sotoodeh, Coating Application for Piping, Valves and Actuators in Offshore Oil and Gas Industry, 2023
Steam cleaning is a cleaning process that involves using low-pressure steam to remove soluble substances from a metal surface. It can be used to remove surface contaminants such as oil, grease, salt and dirt. Detergent may be added to the steam for better cleaning; in such a case, the substrate should be washed and cleaned afterward with fresh water. The definition used for steam cleaning in this subsection is provided according to ISO 12944-4. ISO 12944 is titled Paints and varnishes—Corrosion protection of steel structures by protective paint systems; part 4 of this standard refers to types of surfaces and surface preparation.
Novel techniques for cleaning surfaces contaminated with solid particles
Published in Aerosol Science and Technology, 2022
Sergey A. Grinshpun, Michael Yermakov, Xinyi Niu
As to the mechanical group, flushing contaminated surfaces with water is probably the most common mechanical method used for cleaning surfaces contaminated with particles. It is a low-cost but also a low-efficiency approach, which may lead to a significant environmental contamination (Bonnell 2005). Similarly, brushing, wiping, scrubbing, dusting, and vacuuming typically provide a relatively low particle removal efficiency. However, the ability of the listed methods to remove particles has been shown to improve if they are utilized along with other approaches (Bonnell 2005; Rigby 2009a). Another mechanical method is based on the steam cleaning so that the contaminants are released by hot steam jets and subsequently removed by ventilation and air filtration (Bonnell 2005; Reeves 2018). This approach does not inflict any major mechanical damage on the contaminated surface. However, it offers a relatively low particle removal efficiency and may lead to a considerable environmental contamination. The steam cleaning can over-pressurize the cell being decontaminated by introducing rapidly expanding vapors (Bonnell 2005; Reeves 2018). This, in turn, can produce an excessive condensation on the surfaces. The steam can also introduce additional oxygen to the cell which may generate a negative impact on its performance. The last three mechanical methods to mention, abrasive blasting, sponge blasting and CO2 blasting, have common disadvantages, including high risk of the surface damage and environmental contamination (Rigby 2009a, 2009b; Chen and Lepetit 2013). Additionally, these methods are typically associated with producing a large secondary waste stream that must be managed in a certain way.
Investigation on properties of aqueous foams stabilized by aliphatic alcohols and polypropylene glycol
Published in Journal of Dispersion Science and Technology, 2019
Junchao Wang, Guosheng Li, Shulei Li, Yingwei Wang, Yaowen Xing, Zilong Ma, Yijun Cao
In all experiments, water was purified using a Milli-Q water system. The surfactant solutions were prepared at pH 6.8 in the absence of electrolytes, unless otherwise specified. All glassware were rinsed with HNO3, soaked in 4 mol/L NaOH at 50–60 °C for 60 seconds and were rinsed with Milli-Q water, followed by steam cleaning and drying in a clean oven. To ensure that the surfactants were absolutely dispersed in solutions, each surfactant solution was stirred with a high-shear mixing emulsifier at 5000 rpm for 10 minutes. Besides this, each solution was equilibrated for at least 1 hour before use. All measurements were conducted at a constant room temperature: 25 ± 1 °C.
Design and qualification of a bench-scale model for municipal waste-to-energy combustion
Published in Journal of the Air & Waste Management Association, 2022
Robert J. Giraud, Philip H. Taylor, R. Bertrum Diemer, Chin-Pao Huang
Collection efficiency testing was conducted across three replicate tests consistent with plans for high-temperature combustion testing and standard practices for performance tests at full-scale waste-to-energy plants (EPA 2018b). Prior to each experimental run, a thermal blank run was conducted. Following each experimental run (with PFOA in a pyroprobe cartridge) was a steam cleaning run, where nitrogen was used in place of air and where 50 mL of HPLC-grade water was injected into the reactor system over a 75-min period followed by a 20-min N2 purge. Post-run steam cleaning collected any PFOA that may have condensed in the reactor system. Except for the steam cleaning and the 250°C temperature noted above, the other conditions for collection efficiency testing (i.e., gas residence time, exhaust oxygen concentration, exhaust moisture level, and experimental run duration) were set at the levels planned for high-temperature combustion testing. During each of the three types of runs, reactor exhaust was collected in a set of three midget impingers located in a crushed ice bath. Except during steam cleaning, the first two impingers were pre-loaded with HPLC-grade water (Alfa Aesar, Ward Hill, MA). During steam cleaning, the impingers were initially empty in order to collect the condensed steam. The flexible white silicone tubing into the first impinger was rinsed with 5 mL of HPLC-grade water to collect potential condensate from this unheated line. The aqueous impinger samples from each run were weighed before and after addition of this rinsate. These aqueous samples were analyzed for PFOA by MPI Research (State College, PA) via LC/MS/MS based on the approach described by Risha and her coworkers (2005/03). The limit of quantitation (LOQ) was 25 ng L−1, and the limit of detection was 5 ng L−1.